If you think you have a problem with Subsidence please see below. If you still need some advice please contact us.
What is subsidence?
Subsidence is the downward movement of the ground supporting the building. Particular problems arise when the movement varies from one part of the building to another. Subsidence can be caused by:
Certain soils: Clay soils are particularly vulnerable to subsidence since they shrink and swell depending on their moisture content.
Vegetation:Trees and shrubs take moisture from soils causing them to shrink. This is especially so during long periods of dry weather as roots extend in search of water.
Leaking Drains:Damaged drains can soften or wash away the ground beneath the foundations.
Property location:Less commonly, problems may occur where properties are built over, or close to, mine workings.
Other types of ground movement, which can result in cracking and structural damage, are:
Heave: Heave is the upward movement of the ground supporting the building.
Landslip: Landslip is the movement of ground down a slope.
What should you look out for?
The first obvious sign of subsidence is the appearance of cracks. However, not all cracks indicate that there is a problem. Most buildings experience cracking at some time and there is no need to be alarmed by every crack that appears.
Cracks are not uncommon in new properties and newly built extensions. They are likely to be the result of the building settling under its own weight. These usually are nothing to worry about, nor are fine cracks that often appear in newly plastered walls as they dry out. Buildings shrink and swell naturally due to changes in temperature and humidity, which can lead to minor cracks where walls and ceilings meet. These too should not normally be anything to worry about.
What should be looked out for are small, usually diagonal, cracks which suddenly appear in plaster work inside and outside bricks at weak points, such as around doors and windows, especially after long periods of dry weather. These may, but not necessarily, indicate movement in the building’s foundations. The cracks will normally be thicker than the edge of a 10p coin, and usually be wider at the top. Doors and windows may also “stick” due to the distortion of the building.
Can you do anything to reduce the risk?
Yes. Taking a few simple precautions can help reduce the risk of structural damage. Ensure that trees and shrubs are pruned regularly. Expert advice should be sought from an arborist to make sure they are pruned correctly. Regular general maintenance checks should be carried out around a property. Checks should be made for blocked or leaking drains; dirt and leaves cleared from gutters; and pipes checked to make sure there are no splits. Trees and shrubs planted too close to a property are a common cause of problems. You should also consider the proximity of trees to underground drains and buildings including any belonging to neighbours.
The table below shows some typical tree types and safe distances from a property.
If you would like any information regarding Subsidence or any building matter please feel free to contact us here.